Monoamine Hypothesis of Depression
What does the theory say the depressive disorder is caused by?
An imbalance in the monoamine neurotransmitters
Monoamine hypothesis dep
What kind of imbalance takes place>?
A decrease
Monoamine hypothesis dep
What are the nt involved?
Nor-adrenaline, serotonin, dopamine
Monoamine hypothesis dep
What was noticed in the 1950s?
Drugs that decreased these particular nt caused symptoms
similar to depressive disorder
Monoamine hypothesis dep
What are the characteristics associated with nor-adrenaline?
Sleeping, energy, motivation, emotion
Monoamine hypothesis dep
Characteristics of serotonin>?
Mood control, sleeping, hunger
Monoamine hypothesis dep
What other job does serotonin do?
Regulates adrenaline
Monoamine hypothesis dep
What happens if there is a low level of serotonin?
Low level of adrenaline, lack of motivation and pleasure
Monoamine hypothesis dep
Characteristics of dopamine?
Emotion, addiction, pleasure, and cog function
Monoamine hypothesis dep
What does a decreased amount of dopamine explain?
Diminished interest and lack of pleasure
Monoamine hypothesis dep
How many weeks might drugs take to work?
6 weeks
Monoamine hypothesis dep
Why do drugs not work straight away?
Because of a neuro-circulatory change in the brain
Monoamine hypothesis dep
What type of neuro-circulatory changes occur?
Because of the low levels, an up-regulation in the sensitivity
occurs on receptor sites of post-synaptic neuron
Monoamine hypothesis dep
What happens when the nt suddenly become available through
drugs?
A down-regulation occurs in the sensitivity, causes post-synaptic neuron receptors sites to desensitise
Monoamine hypothesis dep
What did kilmeck find? (strength)
He compared the brain of 15 dead patients with and without
depressive disorder found that there were differences in the part of the brain
that produces noradrenaline showing that nd is involved
Monoamine hypothesis dep
What did mcneal and cimbolic find? (strength)
Depressives show a lower level of 5hiaa which is produced
when serotonin is broken down
Monoamine hypothesis dep
What does another biological explanation suggest that goes
against this one?
Suggests that part of the nervous system is involved and
that increased cortisol is associated with depressive disorder, incomplete
Monoamine hypothesis dep
What do MRI scans show about the theory?
There have been differences in those with and without
depressive disorder, specifically a smaller hippocampus, so it is structural
and biochemical
Monoamine hypothesis dep
What is moa-a?
A chemical that removes monoamine nt from the synapse when
they are not needed
Monoamine hypothesis dep
What does too much moa-a mean?
That too much of the nt are being taken away producing
symptoms of depressive disorder
Monoamine hypothesis dep
Comments
Post a Comment
Your Thoughts?